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प्रश्न
Complete the following table:
| Instrument | Number of Convex Lenses |
Use |
| Simple Microscope | .............. | .............. |
| Compound Microscope | .............. | .............. |
| Telescope | .............. | .............. |
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उत्तर
| Instrument | Number of Convex Lenses |
Use |
| Simple Microscope | 1 | Used by watch repairers to view tiny watch parts |
| Compound Microscope | 2 | Used by watch repairers to view tiny watch parts |
| Telescope | 2 | Used to view faraway objects in outer space |
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संबंधित प्रश्न
Draw a ray diagram to show the formation of image in the above situation
A student has obtained a magnified image of a flame on a screen using a convex lens. To draw the corresponding ray diagram to show the image formation, which of the following two rays whose paths after refraction are shown, should he select ?
(A) I and II
(B) II and III
(C) III and IV
(D) I and III
An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed.
If you focus the image of a distant object, whose shape is given below, on a screen using a convex lens, the shape of the image of this object on the screen would be:
(a)
(b)
(c)
(d)
Draw a labelled ray diagram to show how a ray of light is refracted when it passes:
from an optically denser medium into air.
Where should an object be placed in order to use a convex lens as a magnifying glass?
With the help of a labelled diagram explain how a convex lens converges a beam of parallel light rays. Mark the principal axis, optical centre, principal focus and focal length of the convex lens on the diagram.
A convex lens of focal length 8 cm forms a real image of the same size as the object. The distance between object and its image will be:
(a) 8 cm
(b) 16 cm
(c) 24 cm
(d) 32 cm
A burning candle whose flame is 1.5 cm tall is placed at a certain distance in front of a convex lens. An image of candle flame is received on a white screen kept behind the lens. The image of flame also measures 1.5 cm. If f is the focal length of convex lens, the candle is placed:
(a) at f
(b) between f and 2f
(c) at 2f
(d) beyond 2f
A student did an experiment with a convex lens. He put an object at different distances 25 cm, 30 cm, 40 cm, 60 cm and 120 cm from the lens. In each case he measured the distance of the image from the lens. His results were 100 cm, 24 cm, 60 cm, 30 cm and 40 cm, respectively. Unfortunately his results are written in wrong order.
Which of the object distances gives the biggest image?
What kind of lens can form:
am erect diminished image?
An object is placed 20 cm from (a) a converging lens, and (b) a diverging lens, of focal length 15 cm. Calculate the image position and magnification in each case.
Complete the following sentence.
A long-sighted person cannot see ........... objects clearly. Long-sightedness can be corrected by using .............. lenses.
A convex lens forms an inverted image of size same as that of the object which is placed at a distance 60 cm in front of the lens. Find: The position of image
State the position of object, position of image, nature of image when: Convex lens is used in cine projector.
A concave mirror and convex lens are held in water. What changes, if any, do you expect in their focal length?
Which lens can produce a real and inverted image of an object?
Which of the following statements is true?
Distinguish between:
Concave lens and Convex Lens
Distinguish between Concave lens and Convex Lens.
